[Solved] Get NVIDIA 396.54.09 (beta) with vulkan driver

Hi community,in order to fix an issue with Witcher 3 on Steam Play I need to install an NVIDIA driver with support for Vulkan 1.1.88. Steam Play uses Proton (a wine fork) and DXVK in order to run Windows Games on SteamOS/Steam for Linux.According to this page the issue I'm facing is fixed in the current version of DXVK. However in order for it to work I need a graphics driver that supports "VK_EXT_transform_feedback".It seems that support for Vulkan 1.1.88 was introduced in the NVIDIA 396 Beta driver but still hasn't landed in 415 stable. (Also some redditors have mentioned that 396 Beta comes with improved performance for Vulkan and therefore DXVK)

I tried the standard "nvidia" driver package and the "nvidia-beta-all" package from AUR just to make sure. But for neither of them "VK_EXT_transform_feedback" is listed as supported in vulkaninfo. And both seem to implement Vulkan 1.1.85.

Is there a way I can get this to work with Arch Repository or AUR Packages? I haven't found anything, but I figured it doesn't hurt to ask. If not how save is it to install the driver directly from NVIDIA? (Referring to the warning on the Arch Wiki NVIDIA page)